Publication Abstract

Proceedings - Fourth International Conference - Piling and Deep Foundations, 1991, Stresa, Italy, (DFI)

70 A new model of LPC removable extensometer
M.G. Bustamante & B. Doix Laboratories Central des Points et Chausses, Paris, France

Since 1972, when LPC removable extensometers were developed to determine skin friction and point load, hundreds of full-scale tests have been performed on all kinds of deep foundations using this equipment. Initially conceived to replace existing strain measuring devices, such as tell- tales, bonded gauges, and acoustic strain gauges, the LPC removable extensometer quickly proved its superiority in terms of cost, versatility and adaptability to different types of deep foundations and soil configurations, and measurement quality. These advantages, which still apply, have motivated the search for improvements in the following respects: a) faster assembly and dismantling; b) larger number of measuring points; c) lower total weight; d) simpler maintenance; e) adaptability to larger tube diameters. The new EX 89 extensometer satisfies all of these desiderata. While retaining the advantages of the first models for piles of standard lengths, the new extensometer is substantially more effective in monitoring foundations with extremely long shafts, common in offshore applications.

 article #509; publication #37 (IC-1991-IT)